Pressure cooker



Dec. 17, 1940. E. R. HAMILTQN PRESSURE COOKER 3 Sheets-Sheet` 2 Filed Jan. 3l, 1938 IN VEN TDF? Dec. l7, 1940. a R HAMILroN PRESSURE zooxnn Filed Jan. 31, 195s s sheets-sheet s u aa i Z5 l a 4 i l I 2 |al ,a 3

as ze S li [I6 [l5 6 ISJL W l. l leV l /lllllllll 'INVENTOH EVRETT R. HAMILTON By am, ATTORNEYS Patented Dec. 17,` 1940 UNITED STATES vPATENT OFFICE PRESSURE COOKER Application January 31, 1938, Serial No. 187,926

6 Claims.

This invention relates -to new and useful improvements in pressure cookers of the general lcharacter disclosed in Patent No. 2,022,868, granted to Carl Nelson December 3, 1935.

5 An object of the present invention is to provide a simple fool-proof mechanism for securing the cover of the cooker in sealing engagement with the cookerI body, whereby the cover cannot accidentally be blown olf the cooker when the cover lo securing means is operated to release the cover.

A further object is to provide a pressure cooker .comprising a body havinga plurality of inwardly: projecting lugs provided adjacent its upper end or mouth and having an annular seat arranged y being provided whereby the cover must be bodily lifted out of engagement with its seat before it can be relatively rotated to permit its complete removal from the cooker body.

A further object is to provide a pressure cooker comprising a cover having means for securing it in sealing engagement' with the cooker body, said securing means comprising a plurality of lugsv provided respectively, on the cooker body and 30' cover, and a lock ring having means adapted to be moved into interlocking engagement with the lugs on the cooker body, said lugs being so arranged on their .respective parts that the cover must be positioned on the cooker body atl a predetermined point before it can vbe rotated to a Vposition to engage theseat, and the lugs on the lock 4ring and cooker body having faces slightly inclined to the vertical, which inclined faces coact to force the cover into sealing engagement with the-seat, when the lock ring is relatively rotated with respect to the cooker body and cover,

and said lock ring having a plurality yof 4clamping i In the accompanying drawings there has been disclosed a structure designed to carry out the.

various objects of the invention, but it is to be understood that the invention is not connned to i the exact features shown as various changes may be madewithin the scope of the claims which follow.

In the drawings:

- Figure 1 is a top` view of my improved pressure cooker; I 5 Figure 2 is a similarview on a slightly larger scale, with the lock ring removed, and partially broken away to more clearly show the arrangement of the lugs on the cooker body and cover;

Figure 3 is a view similar to Figure 2', showing 1() the cover positioned Awhereby it may be conveniently removed from the cooker body;

Figure'4 lis a detail sectional view in perspective showing the preferred construction of the mouth of the cooker body;

Figure 5 is a detail sectional view on the line 5-5 of Figure 2, showing the clamping screws of the lock ring operated to force the cover into sealing engagement with its seat;

Figure 6 is a detail sectional view on the line 20 lie-6 of Figure 3, showing the cover loosely supportedin the mouth of the cooker body'and out of engagement with its seat;

Figure 7 is a View showing the lock ring removed from the cover; and

Figure 8 is a view showing the cover removed from the cooker body.

In the selected embodiment of the invention here shown,`there is illustrated for purposes ofA Y disclosure, a portion of a pressure cooker com- 30 prising a body 2 shown having an enlargement 3 at its upper Vend. whose wall deflnes the usual mouth of the cookerbody. A plurality of in` wardly projecting lugs 4 are provided on the wall 3 of the cooker body. These lugs are spaced 35 equi-distant apart and three lugs are preferably provided, although it is to`be understood that the number of lugs used has no particular bearing upon the scope of the invention. Y

An annular shoulder 5 is provided on the wall 40 portion 3 andis `spaced downwardly from the lowerfaces of thelugs l, as clearly illustrated in Figure 4. A plurality-of recesses 6 are provided in the shoulder 5 for purposes subsequently td be 4 described. Y

A An annular seat 'l is formed in the mouth of the cooker body below the vlugs I `and annular shoulder 5, as best shown in Figure 4. This seat ispreferably tapered, as shown, and/has a com- 50 paratively narrow face, whereby the cover may readily be pressed or forced into sealing engagement therewith. 'I'he cover, as best illustrated in Figures 5 and 8, comprises an upper dome-shaped wall I and a cylindrical wall 9 adapted to receive Il tively, as best illustrated in Figure 3.

A diameter or radius short or low, of the lugs I6 spaces |4 between the inwardlyprojecting lugsV 4 of the cooker mouth. e peripheries of the lugs I3 are stepped to provide, in effect, relatively long and short lugs I5 and I6, respec- The is slightly less -than the diameter of the inner cylindrical face I1 of the shoulder 5, and the diameter ofthe highor long lugs |5 is slightly '15 less than the inside diameterV of the wall 3.

It will also be noted, by reference to Figure 3,

that the combined. over all length of each lug I3, including the lugs I54 and l5, is slightly less than the width of one ofthe gaps I4, whereby the lugs I3 may readily pass through said gaps,` when placing the cover-uponthe cooker body. 'I'he cover, as shown in Figures 5, 6, and 8, also comprises a depending annular fiange I8 having an outer tapered face I9 adapted to engage the tapered seat 1 of the cooker mouth.4

.When the cover is .initially placed upon the cooker body, the lugs I5 will engage the annular shoulder 5 before the tapered face I9 of the cover engages the seat 1, as clearly' illustrated in Figure 6. The cover is then rotated in a counter clock-wise direction from the position shown in Figure 3 until the relatively longer lugs I5 drop into the recesses 6, provided in the annular shoulder 5.

, I5 will pass under the inwardly projecting lugs 4 of the cooker mouth, wherebywhen the lugs I54 are received in the recesses V6 to permit theflange I8 of the cover,to drop' into engagement 40"with theseat 1, the relatively shorter or low lugs I6 will be positioned beneath the inwardly projecting` lugs .4 of the cooker mouth. When the lugs I6 are so positioned, it will readily be seen, by reference to Figure 2, that the cover cannot be completely removedv from the cooker body by lifting .it straight upwardly because of the relatively lowerlugs I6 engaging the lugs 4 of the cooker body.4 To completely remove the cover from the cooker body, the cover must be 6o rotated to substantially the position shown in Figure 3. y

The means Jprovided for securing the cover in leak-tight engagement with' the seat 'I is best illustrated in Figure 7, and comprises the lock ring llwhfch, as shown in Figures v5 and 7, has an annular depending flange 2| provienand with a plurality of radial lugsl22 spaced apart equi-distant around the circumference bf the ange 2|. The-'lugs 22'are of-such size as to readily pass through the gaps '|4 provided between the lugs `4 of the-cooker body.. The lugs 22 of the lock ring have their upper faces 23 slightly inclined to the vertical and adapted .to engage the bottom faces 24 of the lugs.l4 of '65 the' cokerbody, as shown in Figure 5. The lower'or bottom Aedge of the flange 2| of the lock ring is adapted to engagethe upper surface ofthe flange I2 of the cover, as shown at thelef't hand side of Figure 5'. 'I'he lock ring is 7 also provided with a bore 2l adapted to receive thev cylindrical wallportion2 9 of thecover, A plurality of suitable clamping screws 25 are provided in the lock ring each provided with a. hea'd 25 shown having hexagonal sockets 21 therein adapted to receive a 'suitable instru- Before the lugs I5 drop` 35 into'the recesses 5, the relatively shorter lugs mentality for rotating or operating the screws 25 to secure the cover to its seat or release it` therefrom. The lock ring is also provided with suitable hand grips 28, whereby it may be conveniently rotated to move its lugs 22 into or out 5 of locking engagement with the lugs 4 of the cooker body.-

It willalso be noted, by reference to Figure 3,

. that the cover is provided with suitable handles 29, whereby it may be conveniently rotated upon 1d the cooker body in the operation ofsecuring .the cover thereto or removing it therefrom.

simple and inexpensive in construction, where, 25

by the cooker may be manufactured at small cost. vThe lugs on the cooker body and cover are sol arranged that the cover cannot be moved into engagement with its seat until it has been moved to a predetermined position on the cooker body, whereby the relatively shorter or lower lugs I6 are positioned beneath the lugs 4 of the cooker body.

When so pitioned, the ,cover cannot be, lifted vertically out of engagement with its seat u to completely remove it from the cooker body. A s previously stated, when the cover is initiallyl moved out of engagement with the seat 1, the

vrelatively lower lugs I6 will impinge against the bottom faces of the lugs 4, thereby requiring 40 that the cover be relatively rotated from thel 3 position shown in Figure 2 to the position shown in Figure 3, before it can be completelyremoved from the cooker body.

By so arranging the lugs on the cooker body 45 and cover, should the cover accidentailybe re-l leased from its seat before releasing the pressure from within the cooker body, it cannot be accidentally blown from the' cooker because of the' lugs I8 engaging the lugs 4 of the cooker body.l 5

When the lock ring is thus released before the pressure in the cooker is released, the pressure within the cooker body may lift the cover olf its seat sufficiently to permit .the pressure to escape to the atmosphere Ithrough the gap pro. vided between the ange Il of the cover and the seat 1, as will be clearly understood by reference to Figure 6. Thus. the lugs I4 and 4 cooperate to ,provide a safety device for preventing the cover from vaccidentally being blown ofi' the o cookerbody, should it be released before the pressure therein has been exhausted or been released to the atmosphere.

When the cover' has been rotated to the position, Ashown m Figure 2, the lock ring is placed 05 thereon, as shown in Figure 5, and the clamp-A ing screws 25 rotated,whereby the -lugs 22 ofthe lock ring will engage the lugs 4 of the cooker body and thus cause the cover to be forced into 7' sealing engagement with. the seat 1, when the clamping screws 25 are operated.

In the structure illustrated in the drawings. the lugs |5vand are so arrangedthat when the cover is rotated in a clockwise direction from i the position shownin Figure 3, the relatively longer lugs I will drop into the recesses 6 provided in the shoulder 5thereby preventing furl ther rotation'of the cover on the cooker body, and permitting the cover to sealingly engage the 5 seat 1. When the cover is lifted out of engage-Y ment with its seat and rotated from the position shown in Figure 2 that shown in Figure 3, or to a position whereby it may readily be lifted cornpletely off the cooker, a suitable stop, not shown in the drawings, is engaged by the cover, thereby` to prevent it from over-running the position shown in Figure `3. ,f

I claim as my invention: i 1. A pressure cooker comprising a body having a plurality of inwardly projecting lugs adjacent its upper edge, an annular seat on said body spaced downwardly from said lugs, a cover having a portion adaptedto sealingly engage said seat, projecting means on the periphery of the cover adapted to be received between the lugs on' the cooker body, an annular shoulder. on the cooker body between said inwardly projecting lugs and the seat adapted to be engaged by the projecting means on the cover, when the cover is initially placed on the cooker body, thereby to prevent the cover from sealingly engaging the 1 seat, said vannular shoulder having recesses therein adapted to receive the projecting means on the cover, when the cover is rotated'to a predetermined position on the cooker body, thereby to permit the cover to sealingly engage said seat,

means for forcing the cover into sealing engagement with the seat, and the inwardly projecting lugs on the cooker body and the projecting means on the cover cooperating to provide a safety means for preventingthe cover from being blown off the cooker body when the cover is initially released from the seatv and thecooker is under pressure. 40 2. A pressure cooker comprising a body having a plurality Vof inwardly projecting lugs adjacent its upper edge lspaced. apart circumferentially of said body, an annular seat below said lugs, a cover having a portion adapted to sealingly engage said seat, a plurality of lugs on the periph-- ery of the cover adapted to be received between the lugs on the cooker body, an annular shoulder on the cooker body located at an elevation bei tween the inwardly projecting lugs and the seat thereof adapted to be engaged by the lugs on the cover, when the cover is initially placed on, the cooker body, thereby to prevent the vcover from sealingly engaging the seat,I said annular shoulder having recesses therein adapted to receive the lugs one the cover, when the cover is rotated to a predetermined position von said shoulder, thereby to permit the cover to sealingly^ vengage'said seat, means for forcing the cover into sealing engagement with the seat, and the lugs on the cooker body and cover, respectively,

-cooperating to provide a safety means forpren venting the cover from being blown off the cooker f body, when the cover is initially released from the seat and the cooker is lunder pressure.

3. A pressure cookercomprising a body having?- a plurality of inwardly'projectlng lugs adjacent its upper edge, an annular seat 4onf-said body spaced downwardly from said lugs, a cover havh ing a portion adaptedl to sealingly engage said 0' seat, a plurality of lugs on the periphery of the cover adapted to be received/between the lugs on the cooker body, an annularshoulder on the cooker body located at an elevation between said inwardly projecting lugs and the'seat thereof "5 adapted to be engaged by the lugs on the cover,

the cooker body, means on the cooker body/be'- when the cover is initially placed on the cooker body, thereby to prevent the cover from sealingly engaging the seat,` said annular shoulder having recesses therein adapted to receive the lugs on the cover, when the cover is rotated to a predetermined position on the cooker body, thereby to permit the cover to sealingly engage said seat, means for forcing the cover into sealing engagement with the seat, and the lugs on the cooker body and cover, respectively cooperating to pro- 10 lvide a safety means for preventing the cover from being blown off the cooker body when the cover is initially released from the seat and the cooker is under pressure, said safety means requiring that the cover be relatively rotated upon the cooker body before the cover can be completely lremoved from the cooker.

"4. A pressure cooker comprising a body having a plurality of inwardly projecting lugs adjacent itsuDDer edge, an annular seat onl said body spaced downwardly from said lugs, a cover having a depending flange adapted to sealingly engage said seat, aplurality of radial lugs on the cover adapted to be received between the lugs on 25 tween `said inwardly projecting lugs and the seat adapted to be engaged by the lugs on the cover, i when the cover is initially'placed on the cooker body, thereby 'to prevent the depending aange of the cover .from sealingly engaging the seat, 30 means whereby when the cover is rotated tol a predetermined position on the cooker body, its

'flange will sealingly engage saidA seat,-a clamping ring on the cover having meansarranged for interlocking engagement with the lugs on the cooker body thereby to secure the coverv to the seat, andthe lugs on the cooker body and cover cooperating to prevent the cover from being' blown from the cooker body, when the clamping ring is initially operated to releasev the cover from its seat and the cooker is under pressure.

5. A pressure cooker comprising a body having a plurality of inwardly projecting lugs adjacent its upper edge, an annular seat on said body spaced downwardly from said lugs, a cover having a depending ange adapted to sealingly engage said seat, a plurality of radial lugs on the cover each having a stepped periphery, `whereby a plurality of high and low' lugs are provided,.a shoulderA on the` cooker body between the in wardly projecting lugs and the seat thereof adapted t be engaged by the relatively higher vlugs of the cover, when the cover is initially placed on the cooker body, thereby to prevent the cover from sealingly engaging theseat, recesses in said shoulderfadapted toreceive said higher lugs, when the cove is rotated to a'predetermined position on the cooker body, wherebythe cover flange may move into sealing engagement' with said seat, the relatively lower lugs of the cover being positioned'beneath the inwardly projecting lugs on the cooker body, when the cover isengaged with its seat, whereby the cover can- 1 not be removed' from the cooker -body without relatively rotating it thereon, and \a lock ring rotatably mounted onl the cover and having a plurality of radial lugs adapted to engage the lugs seat, a' plurality of` rad-iallugs on thevcover each 75 lugs thereof are positioned beneath the inwardly projecting lugs on the cooker body, whereby the cover cannot be removed from the cooker body without relatively rotating it'thereon, a lock ring rotatably mounted on the cover and having radial lugs adapted to interlock with the lugs on the cooker body, and a plurality of screw elements in the lock ring having means whereby lthey may be conveniently operated to force the cover into leak-tight engagement with said seat. l0

EVERETT R. HAMILTON. 

